All I can tell you is I bought a couple of not-awful purple armor items from the AH and an OK blue bow, a couple of Hit runes and started running T2 dungeons to get marks to get better gear. If you don't know the fights I'd probably run a few T1 dungeons first to get the feel of the ramped-up dungeons. But you can gear yourself fairly decently to get into T2's with plat. If you have a metric ton of plat (as in several hundred) then you're looking at the Deathstalker set and epic weapons.

If you haven't spent your favor at all, how much do you have? I had like 65k when I hit 50 on my mage and just went and bought all of the pvp gear i could get and ran t1's w\ it til I could get better stuff. I'd suggest doing the same. Then as you get dungeon drops, you can replace gear for +hit so you can progress to T2's and further.

You may wanna look in the AH and grab something like a Spined Compound Bow (I've seen them listed for as little as 3-5p, but have bought 1 for 18 which was worth it at the time ) , or if you have some 100p to spend and can find somebody who's been grinding ember isle rep, you could get an enchanted shadethorn bow made ( what I'm currently using ).

Or maybe you'll have better luck w\ dungeon drops and get a nice bow there.